


Heat and Confusion

by Kleptomaniac_Can_Opener



Category: Ao no Exorcist | Blue Exorcist
Genre: Blue Balls, Like serious Heat, M/M, Rin needs to get laid, So much blue balling, Twincest, going into heat, just saying, twincest is wincest
Language: English
Status: Completed
Published: 2017-11-03
Updated: 2017-11-03
Packaged: 2019-01-28 21:48:36
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 5,919
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12616292
Author URL: https://archiveofourown.org/users/Kleptomaniac_Can_Opener/pseuds/Kleptomaniac_Can_Opener
Summary: Rin’s growing demonic nature has caused the usual hormonal itch to become… Insistent.





	Heat and Confusion

**Author's Note:**

> Written for my friend Silverfoxfire. :D  
> [Go see the cover art!](https://www.patreon.com/posts/fanfiction-15193490)  
> [Rin art](https://www.patreon.com/posts/fanfiction-8147845)  
> [Yukio art](https://www.patreon.com/posts/8558632)  
> 

Shura checked Rin’s temperature, then the size and reactivity of his pupils. She hummed to herself in thought as she used her fingers to examine lymphoid glands. “Goods news is, you’re not sick,” she concluded.  
“How the hell is that possible?” Rin groaned. He was sweating like he had gone on a long run, and his cheeks were flushed pink.

The Upper-First Class exorcist waved a hand over the table next to them towards a set of tubes filled with different colored liquids. “They all tested negative. As far as I can tell you’re having a hot flash, no biggie, just hormones being hormones.” She shoved her red and blonde ponytail back over her bare shoulder as she stood to stretch her long body. “Go see chicken shit or Moriyama if you doubt my assessment.”  
“No!”

Shura’s brows shot up. “Oh?” She watched as the older Okumura twin shook his head, blue eyes refusing to meet hers. “Well, whatever. You can’t practice like this, take a cold shower.”

Rin took her advice and went straight to the bath as soon as he was in the dorm. He must have stood under the cold spray for an hour before he felt any better. Once he was dry again he went ahead and pulled on his sleep pants. If he wasn’t going back out, there was no sense putting on a uniform or dirtying his regular clothes.

His lion-like tail swung and curled in irritation behind him, then it thumped on the bed after he flopped facedown on it. He stared at the wall, listless and restless. He still felt much too warm just underneath his skin.

The blunet flipped onto his back with an annoyed growl, his tail thumping the side of the mattress now. “This is fucking stupid. If I’m not sick then what the hell is wrong with me?” Rin threw an arm over his eyes, blocking out the fading light coming through the window shades. “I don’t wanna get lectured about my health, how am I gonna hide this from Yukio? Should I stay in another room? Stay in the kitchen all night? Shit, this is stupid!” His tail gave another solid wham.

The sound of footsteps caught his attention, pointed ears perked up. “That’s not Yukio.” The steps stopped in front of the door moments before a hard knock. “Hey, Okumura,” barked Ryuji Suguro, “is your dumb self in there?”  
“Fuck off, rooster head!”  
“I need your part of the assignment, moron!” He kicked the door.

Rin’s senses flared. He could smell the other male. He could make out Bon’s musk, his sweat, the body gel and shampoo he used, the scents on his clothes, even the leather of his shoes. He slapped his hands over his nose. “Mmph!”

Suguro paused his wood abuse at the strange sound. “Not that I care, but are you alright?”  
“I-I’m fine! Go away!” His voice was muffled by both his hands and the door, garbling his words.  
“Okumura?” The young monk waited for Rin to properly respond, but after a couple minutes he realized one wasn’t forthcoming. “Okumura!” He banged on the door with a fist. “Hey! Answer me!”

There was a series of thumps, then the door was thrown open. “I said go away!” Rin bellowed. The smaller male looked a wreck. His sleep pants were disheveled and half off his hips, his blue hair stuck up in all directions, and even his tail looked frazzled. He was flushed and sweating heavily.

Then a wave of heat smacked Suguro in the face. He stumbled back a step, his head swimming as his senses processed a spicy but sweet scent. His uniform was suddenly too hot. He pulled in a deep breath, and he swallowed as his mouth started salivating.

Blue eyes met brown.  
Rin yanked Suguro closer by the collar, visibly sniffing him and groaning.

The monk didn’t know when his hands had moved, but he grabbed his fellow Exwire by his ass. He wasn’t sure which of them growled, maybe they both did. He was having trouble thinking of anything beyond pinning Rin down and having his way with him. “What are you doing?” he finally ground out.  
“Who knows,” the blunet murmured, then their lips crashed together.

Clothing ended up on the floor between the doorway to the bed, which they didn’t fully make it to. Rin hung half off of the side while Bon grounded their hips together, his own pants still somehow on while the smaller teen was naked. Nails scratched down the monk’s broad back even as he trapped the other male against the side of the mattress.

He came back to himself for a moment when the demon tail wrapped around his arm.

Suguro stared at it in confusion, trying to figure out how they had ended up in their current position. He leaned back and took in their conditions.

Rin had bites along his clavicle, and he was slick with the precum flowing over his belly from his hard shaft.  
The crotch of his pants were soaked in both of their fluids, and he was sporting a few hickeys on his chest. His hands were still filled with Rin’s firm buns.

The monk didn’t have a chance to react further before he was thrown away from the blunet and the back of his head slammed against the floor. “Shit!” He grabbed where he had hit with one hand and jumped to his feet, but any curses died on his tongue.

Yukio was in his full Exorcist uniform, and he looked murderous even with his guns still holstered.

“O-Okumura-sensei!” With his adrenaline pumping, his head cleared faster. He had just been bumping and grinding with Rin like their lives had depended on it.  
“Leave.” The teacher’s tone was cold and clipped.

Bon responded with a curt nod and ran out, barely having the mind to grab his discarded clothes along the way.  
The door slammed shut with a thunderous bang behind him.

Rin’s mind was in a haze, a fluffy and hot haze. His blood was rushing loudly between his ears in tandem with his hammering heart, yet he acutely picked up the faintest sounds. Yukio’s pulse was racing, the leather of his holsters creaked. Sweat gradually trickled down the side of his neck with a wet sliding noise. Even his smoldering teal glare seemed to be making a high-pitched whining.

Oh. That was him.

His brother’s voice sliced through the encompassing fog. “I can’t believe you. Clean up.”

He didn’t want to clean up, his skin felt too hot, he was burning from the inside like his flames were eating him. He wanted Bon back, Bon had been helping. Who would help him now?

Another whine escaped the back of Rin’s throat and his tail lashed in frustration. He latched to his twin’s coat, ignoring the bite of the belt and holsters. He could scent alpha demon and gunpowder, there was also menthol, and a hint of musk underneath it all.

Yukio smelled…delicious.

“Yukio…” The blunet licked the handle of the gun by his chin. “Ah…”  
“D-Don’t do that!” Yukio shoved at his brother’s head, but Rin didn’t let go. “I said clean up! You’re naked and dripping, it’s gross!”

Rin froze.  
Yukio bit his tongue.

Blue eyes dilated until they were black. Rin jerked away, tail practically twisting into a knot as he came back to himself. “What…what am I doing? Ha ha…” The fake laughter was strained. “This… a joke. It’s a joke.” His eyes were too wide, the irises still overtaken by blown pupils.

Yukio felt frozen as his brother metaphorically imploded. He was jerking around like a caged animal, trapped and confused. “Rin?” A wild, wet gaze locked on him.

The silence screamed.

Rin was a blur out the door. “Niisan!” Yukio’s legs finally moved.

When the younger Okumura caught up, he could hear the shower already on in the dorm bathing hall. He stopped himself from running in as he was. They were both in an upset state, and he was covered in weapons meant for killing demons.

He dressed down to only his pants before moving deeper into the bath hall.

The blunet stood under a deluge of cold water, but it was steaming around him. His tail was wrapped around his hips, and his shoulders were hunched from hugging himself. Teal eyes widen in alarm as he saw drops of blood drip down Rin’s arms.

“Niisan!” He hurried to his older sibling, then slid to a stop when a depressed stare lifted from the ground.  
“Yukio…” Those blue eyes hardened and he jerked his gaze away. “Don’t come near me, I’m sick.”  
“You’re hurting yourself.”

Rin followed Yukio’s gaze until he saw where his nails were digging into his flesh. It took a moment to process, then he dropped his arms to his sides. “Sorry,” he mumbled.

For a long moment there were only the sounds of the shower and their breathing, until the younger brother broke the hush. “I meant the floor.”  
“Huh?” Rin finally lifted his head and looked at his sibling. Yukio’s glasses were protected from the steam with a special coating but that hadn’t stopped the water droplets from clinging to the surface.

Yukio’s expression was serious. “I said that wrong earlier. I meant the floor was gross, not you.” His cheeks stained a deep red. “Because you’re naked, you’re dripping all over the floor, it’s gross. That’s what I meant.”

It was quiet again until Rin started laughing. “It’s so like you to be worried about the floor.” The steaming stopped, then there was a sobbing hitch before his knees wobbled and he sunk to the wet tiles. The shower continued to beat over his exposed back. Yukio’s feet made wet slaps as he walked over, then the punishing downpour was halted with a few twists of a squeaky knob.

“Niisan…” He knelt on one knee, and rested a hand on Rin’s shoulder. “You should dry off before you catch a cold.”  
“Did you get hurt?”  
“Huh?” Yukio pulled back in surprise at the sudden question. “No, why?”  
“You smell like menthol.” Rin lifted his face and sniffed. “Not a lot. Overstretched a muscle?”  
“Oh, no, nothing like that. I could smell you as soon as I stepped into the building and put some under my nose to block it.”

A wet thumb firmly wiped itself across his upper lip then his nostrils. “What are you…?” He pulled in a breath mostly free of the menthol, and shivered. “Niisan, stop.” He grabbed his wrist to keep him from rubbing off what was left of the ointment.  
“Isn’t that better, Yukio?” Rin purred, shifting closer to his twin. The droplets left on his skin were evaporating away.

“You need to stop,” Yukio pushed.  
“Then stop me.” As if pulled in by gravity, Rin leaned into the last of the space between them and brushed their lips together. Both of his brother’s powerful hands grabbed his arms and he forced that space between them again.  
“Don’t. This isn’t you.”  
“Feels like me.” Rin rubbed his drying tail down Yukio’s back.

Those fingers tightened their grip and a hot puff of air escaped a mouth opened in a silent O.

Rin leaned in once more. “Teach me a lesson, Yukio.” He whispered directly into his brother’s ear. “Sen-sei.”

In a blur, the older Okumura found himself on his back with the larger male’s weight pinning him down. “Stop it!” The hands still holding his arms shook him hard. “Stop! You’re speaking temptations!” Yukio nearly bit his tongue when Rin’s tail firmly coiled around his covered crotch.  
“According to your Exwire it’s exactly what you want.” An alluring smile was painted on his face, his blue eyes were dark and lidded. “When’s the last time he’s been rewarded, sensei?” His tail squeezed and rubbed. “Let him teach the new recruit his place.”

Rin’s pheromones were filling the entire room. Yukio could feel his resolve crumbling with every inhalation. In a burst of willpower he shot to his feet and turned the shower on full blast.

“FUCK! That’s cold!” Rin flew across the room to escape the unwanted deluge.

Yukio adjusted his glasses with one hand. The flood of water was helping to wash away his twin’s tantalizing scent and it cleared his head. “I’m going to clean the room. Get yourself under control.”

His pace was brisk all the way to the room, his normally steady hands fumbling with his tube of menthol as he carried his clothes. Yukio only took the time to redress once he had the ointment slathered under his nose. He knew without it, that entering their quarters would be like getting punched in the face. He had no idea what was going on with his brother, he still couldn’t believe he was about to fornicate in their shared quarters and with one of his classmates nonetheless, but he was going to get to the bottom of it once he had their room back in order.

He swung the door open and threw in a Holy Water grenade. Rin’s pheromones dissipated in clouds of smoke.

Yukio sighed then adjusted his glasses—it was time to clean up.

He had wiped down the floor and was in the middle of changing the bedsheets when there was a pop and a cloud of smoke in the middle of the room. “Guten tag,” sang the familiar voice of the demon Mephisto, the Chairman of True Cross Academy. Yukio wasn’t in the mood for his antics, and was about to tell the man to return later when he saw the overtly colorful and flower-designed gas mask on the demon's face.  
“What are you doing?”  
“Taking precautions, dear boy.” Mephisto shook a gloved finger as he spoke. “I could smell your brother a building away. It’s quite a twist, who knew he could have Heats?”

“Heats…?” Yukio’s brain grinded to a halt. “That’s not right,” he protested, “he’s my brother!”  
“Oh my, what are the children being taught these days?” Mephisto exaggerated a shocked expression through the mask with huge hand motions. “As I’m sure you’re aware, demons have mating seasons. What you apparently don’t know is that Heats aren’t limited to one sex, and,” he held up two fingers, wiggling them, “it’s not unusual for those demons to have two distinct phases: to sow, and to vessel. Dear Rin wants to be a vessel, meaning,” he brought his arms down to imitate a large belly, “he’s trying to get pregnant. I didn’t think he had it in him being half-human, he’s such a late bloomer.”

“That’s…that’s ridiculous.” Yukio’s stance was stiff, his hand trembling as he adjusted his glasses to sit higher on the bridge of his nose. His jaw was beginning to ache from clenching his teeth too much. “As you said, my brother is still half-human, even though his demon side has manifested his body is still functionally human. Nowhere in the archives have I seen a male of demon descent be capable of such a thing when they have a human body.”

He felt rather than saw the Cheshire grin that split Mephisto’s thin face behind the bulky, flower power headwear. It sent a shiver down his spine and his mouth went bone dry. “But he’s not just any demon descent is he?” the man pointed out. “Rin is the spawn of Satan. Those blue flames he harbors make anything possible.”

Yukio’s hands made fists by his sides and he clenched his teeth again. His thoughts were racing. His brother’s need to perform coitus, and unexpectedly turning his attentions on him when he was cock-blocked from Suguro, was now explained but that didn’t help matters at all. If the Vatican found out about this… A cold shiver shot down his spine.

“By the way, where is your brother?” The demonic chairman removed the mask, his nose lifted to the air. “I don’t smell him on the premises.”

Teal eyes widened in panic at the news, his heart pounded from instant anxiety. “What?”

The young professor rushed back to the shower room, but it was empty. The window by the soaker tubs was open. His blood froze, he hadn’t thought Rin would leave. He hadn’t thought at all, he had been too busy running away. “Niisan…”

Rin held his towel close as he snuck across the grounds by hiding behind bushes, trees, statues, and other such conveniences. As long as he didn’t get caught he’d be fine. It was a good thing that it was getting dark. He had no idea how he’d explain himself if he was seen, and he just knew he’d be labelled a pervert then Yukio would yell at him and who knew if his little brother would still talk to him after that. He may even get kicked out, and where would that leave him?

It was a relief when he finally reached the correct dorm.

With a quick leap to the second story, he rapped on the window of the corner room with his knuckles. “Shima,” he hissed. “Shima, it’s me!” After a moment the window slid open and a bewildered Renzou Shima, still in his school uniform, showed his face.  
“Okumura? What the hell are you doing out here in a towel?”  
“Later! Let me inside and lend me some clothes!”

The pink-haired teen didn’t argue. He backed away to allow his classmate in, and looked around for any possible witnesses before shutting his window again.

“What happened?” He hurried over to his wardrobe to pull out pants and a tee-shirt, they’ll be big on Rin but they’ll work. “And don’t mind my saying, but you look like shit.”

Rin was uncharacteristically quiet and gloomy. Shima could see the stress radiating off the other teen like a beacon. It was disconcerting and it made his chest feel uncomfortable. “Look,” he said as he placed the clothes on his bed next to where Rin was sitting, “I don’t know what happened, but my roommate is at some family thing this weekend. You can stay here until you get your head together.”

“Shima!” The blunet glomped him in a tearful hug. “You’re a true friend!” The pink teen laughed a bit and patted Rin on the head.  
“Sure, sure, just get some pants on.”

Rin pressed his nose closer, taking deep breaths of the pink monk's scent. He smelled of soap, sweat, and something oddly refreshing.

Rin purred.

Shima looked down at him in confusion. “Is that you? Are you purring? Since when did you become a cat?” A spicy scent reached his nose, and he breathed it in. Without meaning to he moaned.

The blunet shifted up, wrapping his arms around his friend’s neck then leaning in for a round of tonsil play. The monk’s arms snapped around Rin’s waist, pulling him tight against the taller male.

The towel fell away with the help of a waving tail. Eager hands grabbed and kneaded Rin’s glorious backside, naked hips grounded against cloth. A thin whine escaped the blunette’s throat.

Shima chuckled. “How cute.” Fingertips slipped between firm buns, and Rin’s knees nearly gave way when his hidden bud was rubbed.  
“Ahn!” He clung to the pink monk and lifted onto his toes to tilt his hips for him. His tail curled and waved as touches continued over such a sensitive area. “Shiiimaaa…”

The pink teen didn’t even think about it as he led his classmate to his bed. His friend’s scent was intoxicating and the other male was obviously willing. Who was he to deny Rin a little play?

He laid the blunet down and immediately attacked his chest with his lips and teeth, teasing the flesh then abusing the dusky nipples. Rin squirmed and moaned under him, his tail twisting in the bedsheets. “More,” he half demanded and half begged. “More, Shima.”

Shima captured the blood-dark cock with one hand and stroked it in time to his rubbing Rin’s entrance. “Like this?” he teased. He was enjoying the expressions flitting across his friend’s face way too much.  
“More,” Rin whined now, his frustration building. He had already been denied twice!

The pink-haired teen licked his lips. “Fine, fine.” He pulled away, tearing another cry from the blunet, so he could push off his pants. He would worry about his shirt later if it got in the way. His dick was wet with precum and matched his hair in color. He knew from experience that it’s not a bad size either—he’s never left anyone unsatisfied at any rate—and more than one lover praised the upward curve.

Rin made a happy sound at the sight of it. “That, give me that!”

The door slammed open, snapping both of their attention to the far side of the room. Yukio rushed inside with the gas mask-wearing Mephisto right behind him. Shima blanched. “Okumura-sensei?! Chairman?!”

Yukio grabbed the monk and yanked him away from his twin. He held a jar of menthol to the other teen’s face. “Clear your senses,” he ordered. Shima couldn’t help but breathe it in. It made him dizzy and he sagged against his teacher, confused and disoriented.

Mephisto for his part, pointed his walking stick at the agitated spawn of Satan. “Drei, zwei, eins.” A Cuckoo Clock shaped like a tiny house popped out of a puff of smoke.  
“Kuchuu!” A stuffed bunny with wings flew out of the pink door over the time face and grabbed Rin, dragging him into the clock.  
“Hey!”

The Chairman snapped his fingers and the clock disappeared. “There, nice and safe now,” he declared. When he glanced over to the two humans, his hidden grin widened. They were both embarrassed and acting awkward as Shima corrected his clothes, the boy uncharacteristically stuttering his bafflement over recent events. “Calm yourself, young Shima, you did nothing wrong. Think of it as being bewitched.”  
“Bewitched? By what?” Shima questioned, red in the face and voice higher pitched than normal.

The demon removed the flower power gas mask to reveal the face-splitting smile, baring more teeth than the young student was comfortable with. “Why nature, of course.”  
“Forget this ever happened, Shima-kun,” Yukio interrupted. “Neither of you were acting under your own power, so forget it.”  
“Like you have to tell me that,” that pink-haired male yelled. “I’m never going to be able to look him in the face again!”

It took some time, but Yukio was able to calm Shima down so they could leave the Exwire alone. They would have to talk to Suguro later as well.

The young teacher felt like Godzilla had been trampling on his head in an attempt to reenact a tap dance routine. He rubbed his eyes under his glasses before adjusting them to properly glare at Mephisto. They had moved to the demon’s office to continue discussing the business of his brother.

“To put it bluntly,” the demon said with his lips imitating the Cheshire Cat, “there aren’t many we can bring this matter to.” Yukio resisted sighing his irritation. “It looks like young Okumura requires a full mating to come down from his Heat. The only people who know of his true nature are,” he waved a hand between them, “us, Shura, and the other Exwires.”

Yukio felt his hackles rise. “No, absolutely not.” He crossed his arms and increased the power of his glare, but it didn’t affect Mephisto at all. Not a surprise, unfortunately. “There’s no way we can get the other students involved, as the head of an educational facility you know that.” The man chuckled.  
“Certainly, but I suppose that leaves a teacher, doesn’t it? As a sex education lesson, you could say.”

The younger Okumura twin felt pain in his jaw from how hard he was gritting his teeth. “Shura would never agree, and even if she did I object. Their relationship would never be the same, and she has to answer to the Vatican. Think of the position that would put them in.”  
“Oh?” The lazy ease of the chairman’s expression said that he knew Yukio would respond the way he had. “Would my authority be sufficient enough to satisfy the Vatican? A demon to handle a demon.”  
“No!” Yukio hadn’t realized how violently he had screamed his opposition to that idea until Mephisto broke out into a too amused cackle that stretch out for several seconds.

“Then that leaves one option, Okumura-sensei,” he purred in the silkiest of tone. “You.”

It was like a physical strike, forcing Yukio to step back in surprise, eyes wide behind his spectacles. “What?”  
“You are the only one who can bring your brother down from his mating high. It’s what you want, isn’t it?”  
“That’s not true,” he spat in denial. He was shaking with the rage the accusation had induced.

Mephisto only laughed again. “Drei, zwei, eins!” In a puff, a small brown vial landed in the demon’s gloved hand. “You’ll need this.”  
“What is it?” Yukio managed to ground out.  
“Demon-grade birth control.”

In the Cuckoo Clock dimension, Rin was on a four poster bed surrounded by fluffy cushions and other items of comfort, but it did nothing to cool his boiling blood. He could hardly think around the burning need in his gut and groin, not after being denied a third time. Blue balls that many times in short succession was torture. His hand was fisted around his throbbing, crying cock and pumping it like it was going out of style but it wasn’t enough.

He needed more.  
More that made his toes curl and his tail thump.  
More that made him gasp and cry and bite his lip, and his cock was weeping and weeping but he felt empty inside.  
So, so empty.

It felt like he was going insane.

“Niisan.” That single word cut through the fog in a flash. Blue eyes popped open to stare in horror at Yukio’s large frame by the side of the bed.  
“Y-Y-Yu…” Rin’s throat was paralyzed. He whipped the thick comforter over himself, hiding from his twin’s gaze. His heart was pounding in his ears and his blood kept rushing like whitewater rapids. He was starkly aware of how he smelled of sex. “Get out of here,” he managed to muffle out. “There’s something wrong with me! Go away before I go crazy again!”

The silence stretched on for an eternity but was in reality only few seconds. “There’s nothing wrong with you, niisan. You’re in Heat.”  
“…what?” Rin rubs his ears. He must have heard Yukio wrong through the blanket.  
“I said you’re in Heat. Remember the cat that kept howling at night when we were kids? We thought it was being bullied until father explained that it was a female in heat and that she was looking for a mate. Right now, you’re the female cat.”

The blunet was in a state of disbelief. He was in Heat? And being in Heat meant that he was looking for a mate? The more he thought about it, the worse he felt. Unfortunately, it didn’t make the burn in his veins lessen. His body was thrumming for sex, and it didn’t care who it was as long as they were healthy and strong. A sharp keening escaped his throat and it only stopped when Yukio started talking again.

“Without interference, there’s no telling when your Heat will dissipate. It’s not as simple as you getting yourself off.” The younger brother pulled in a slow, deep breath as if to steady himself. “To make it stop, you have to have sex.”

The older twin shook in his confines. “This wasn’t how I pictured losing my virginity.”  
“I know. I’m sorry, niisan.”  
“And who the hell am I supposed to do it with?” He couldn’t imagine forcing any of their friends to go through the act with him, not while his mind was still clear. It wasn’t right for his pheromones or whatever to make the choice for them.  
“I’ll be your partner.”

The blanket was thrown off. “That’s not funny, Yukio!” His bellow echoed in the pocket dimensional space. “You’re my younger brother!”  
“I’m not making a bad joke, I don’t find this funny either.” He pinned his twin with hard teal eyes. “I’m doing this to save you. If the Vatican finds out, who knows what they’ll decide. They could order your execution immediately if they think this makes you a threat.” He visibly grit his teeth and his hands were tight fists by his sides. “I won’t let them do that. If it means saving your life, I’ll do it.”

Rin stared at Yukio. Several feelings were battling for dominance inside of him: disbelief, denial, love, trust, need, lust, apologetic, upset, frustrated, want, relief, and so much more. “Yu…kio.”  
“Niisan.” His hands unfisted to cup his brother’s face, stopping before he actually touched his brother. He instead reached into one of the many pouches he had on him. “You need to drink this.”

The blunet wrinkled his nose at the sight of the strange liquid. “What is it?”  
“It’s special medicine to prevent pregnancy.”  
“You’re fucking kidding me,” Rin screeched. “I’m a guy, I don’t need birth control!” Yukio couldn’t blame him for the reaction, and he explained in his calm teaching manner.  
“I’m not kidding. We don’t know if you can have children that way. There’s too many factors involved and we don’t have time to check any of them. We’re taking precautions to prevent that scenario altogether.”

The demon twin slammed his fists against the bed, his anger clear and justified but with nowhere to direct it. Yukio popped the cork and held the vial out to him. “Go on,” he urged. Rin muttered a sharp curse and took the vial, downing it in a single gulp. He blinked in surprise.  
“Huh, kind of tastes like honey.”

After a moment both of the boys broke out laughing at the unexpected turn of events. The tension was still there but the razor edge felt further away.

Neither said anything as Yukio began to undress himself, setting everything to the side in a neat pile. The air was thick as a bale of cotton. Rin’s clawed fingers dug into the bed as his blue gaze kept darting to Yukio’s naked flesh that was gradually revealed one piece of garment at a time. His body was hard and muscled from his field world as an Exorcist. He tingled with that thought, and he felt his groin stir back to life. His breath began to speed up without his consent. His twin’s scent was even more delicious than it had been earlier, no longer tainted by the menthol. He licked his lips and shifted closer to his sibling. 

Yukio took a moment to himself, taking steadying breaths to reinforce his nerves. He had to do this for Rin’s sake, he kept thinking to himself almost like a mantra. Something about it rang hollow, and Mephisto’s mocking laughter echoed in his head.

‘It’s what you want, isn’t? Your brother to yourself.’

Not his exact words, but it was the sentiment. He kept denying it, but the more he felt his twin’s gaze burning into him, the less resistant he was to the idea. Finally, he turned to face the blunet, and this time when he reached to cup his brother’s face he made contact.

Flushed cheeks were hot. Rin was purring like a cat, his lion-like tail waving back and forth in pleasure. Yukio swallowed and dipped down, pulling in a lungful of Rin’s spicy aroma. He groaned as their lips met.

The kisses were fast, hard, and passionate. The heat became sweltering between them, sweat already beaded their forms. Yukio stopped thinking and let his body do what was only natural, answering those mewling cries and begging moans.

He pressed Rin into the bed, forcing his back to bow when he ground their hips together. He bite and sucked on his brother’s shoulder near his neck, his teeth threatening to break skin—to his twin’s approval.

It was wet between Rin’s legs, so wet and slick. He hadn’t thought Rin’s body could do that too, but it looked like he wouldn’t need the lube he had requested. The pungent smell was even more arousing than before. Yukio thought he was going to burst from his skin if he didn’t take the blunet soon.

“Niisan.” He shoved his brother back against the pillows, haphazardly pushing one under Rin’s hips to lift them. He barely knew what he was doing, he had never actually copulated with another male before. He didn’t want to hurt Rin due to his inexperience.

The sudden thought that he should have let the experienced Shima do the job froze him for a split second before filling him to the brim with jealous fury.

Blue eyes dark with need, lust, and want glistened up at him with happiness. “Yukio.”

Yukio bit the thick muscle of his shoulder again and held sharp hips firmly with one powerful hand as he guided his pulsating cock to the virgin entrance. He pushed. Nails dug into his back.

“Hot…” Yukio groaned as he sank smoothly into the clinging warmth, the tightness of Rin’s ass gripping him in a heavenly hug.  
“Good… good, Yukio!” His brother’s eyes were rolling back and his friction-pink mouth glistened with saliva. “More!”

Yukio couldn’t resist that.

Strong hips snapped and bucked, driving deep into Rin’s slim body. The heat, sweat, and musk enclosed around them like an egg. Their cries sounded in their ears, encouraging each other to give more, to take more.

Yukio’s world flipped when Rin abruptly roll them over to straddle his hips. The blunet purred with a sensual expression. “This is a good view.” Then he bounced, making the young teacher arch and buck under him. The brunet grabbed Rin’s waist and forced him to thrust down harder. “AH! Yukio!”

The younger Okumura’s sights had narrowed down to only Rin. Everything else around them was left in a haze.

His sibling threw his head back. “Yukio!” His cock erupted white ribbons of sticky cum, spraying them over taunt bellies and blushed flesh. Yukio bucked again then held his brother down balls deep.  
“Nnh!” He came hard, the rush making him dizzy as he filled Rin’s ass with his seed.

“Oh man…” Rin collapsed atop of Yukio, panting and gasping for air.

Yukio ran his hands over his brother’s back, petting him until his breathing slowed. He rolled them onto their sides, grunting when his soft shaft slipped out. The blunet sleepily cuddled up to him like a kitten.

Rin was cooling to his normal temperature as he nodded off. Yukio released a heavy breath in relief, he didn’t think he could handle another round.

His brother rested quietly, his head pillowed on his shoulder and lips brushing over his clavicle. He looked peaceful this way, his features smooth and free of worry and burden. Yukio threaded his callused fingers through the fine hairs on the back of Rin’s neck and took in his brother’s sex-soaked scent. A smothering heat blossomed in his chest.

“I’ll protect you, no matter what happens. I won’t let anyone take you from me.” He tightened his arm around Rin’s waist.

The world tinged with blue and it felt like the most natural thing in the world, just like having his dear brother in his arms.

“No one else can have you, niisan.”

**Author's Note:**

> [Want to stay updated on my art and stories?](http://dawneastpoint.deviantart.com/journal/Check-Here-for-my-Updates-638603365)  
>  It'll be two steps because I'm not allowed to mention my personal blog on here.


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